What happens is that they die and create anew job to fill, what do you do when something of yours breaks? You most likely replace it or get a new one. Why waste your time on something that you are going to have to "fix/"repair"?
If we approve everyone that will only make things worse, because we would have to raise every aspect of our societies. Some areas will have to do with less and this could cause more problems along the road.
I believe that we should take care of ourselves. If we expect for the government to take care of us, then we will become dependent, and careless about our spending. Seeing as how it is not our money. We will become like Romney said in one of his debates that "47 percent of Americans are dependent on the government", which i believe is true, the reason why this programs were started was to help out not support. Paul Ryan want to make programs such as a medicaid in to a voucher system where only certain people qualify.